Hello,
Right now, we're looking at a conference in Essen, Germany starting somewhere in the first full week of October, the 11th through the 17th. Ideally, the conference would include one or two weekend days so that those who are unable to get time from work would be able to attend.
I think Essen is fine for everyone living in Paris and generally in Europe, there are "low costs" flights from www.germanwings.com to/from Koln to anywhere in Europe, Thalys and car options available. Time is more a problem for me, I think I could attend only the week-end.
/ David